Folding bicycle



FIG. 1 is a side elevational view of a folding bicycle showing my new design in unfolded condition;

FIG. 2 is a perspective view thereof;

FIG. 3 is a side elevational view thereof in folded condition; and

FIG. 4 is a rear elevational view of FIG. 3. 

The ornamental design for a folding bicycle, as shown and described. 